Doctoral Dissertations

Li Na Ma

Keywords and Phrases

Dissolution behavior; Dissolution kinetics; Structure; Thermal stability

Abstract

"The solubility of phosphate glasses in aqueous solutions can be tailored through compositional control to obtain a wide range of ion release rates required for a variety of applications. The principal objective of this dissertation is to advance the understanding of the dissolution behavior of phosphate glasses in aqueous environments.

Two families of glasses, sodium-iron phosphate (NFP) glasses and sodium-calcium phosphate (NCP) glasses, were evaluated. The dissolution behavior depends on the phosphate anions that constitute the glass structure and the associated metal (Me) cations. The phosphate glass structure, defined by the distribution and average size of phosphate anions and depending on the O/P and Me/P ratios, was determined by high-pressure liquid chromatography and Raman spectroscopy; Mössbauer spectrometry provided information about the coordination environment of iron. This structural information is used to explain the compositional dependence of the thermal properties and crystallization tendency of NFP glasses and melts, and the aqueous corrosion behavior of NFP and NCP glasses.

Phosphate glass dissolution data are fit to different kinetic models which describe the glass dissolution mechanisms. Information about the glass composition and structure is used to predict changes in the pH of leachate solutions, and a model based on the Gibbs free energy of hydration used to explain the compositional dependence of the glass dissolution rates"--Abstract, page iv.

Advisor(s)

Brow, Richard K.

Committee Member(s)

Schlesinger, Mark E.
Day, D. E.
Fahrenholtz, William
Woelk, Klaus

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Materials Science and Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2014

Journal article titles appearing in thesis/dissertation

  • Structural study of Na2--Fe--Fe2O--P2O5 glasses by high-pressure liquid chromatography
  • Structural study of Na2O--FeO--Fe2O--P2O5 glasses by Raman and Mössbauer spectroscopy
  • Crystallization behavior of Na2O--FeO--Fe2O3--P2O5 glasses
  • Dissolution behavior of Na2O--FeO--Fe2O3--P2O5 glasses
  • Dissolution behavior of Na2O--CaO--P2O5 glasses
  • Dissolution behavior of Na2O--FeO--Fe2O3--P2O5 glasses in alkali aqueous solutions

Pagination

xiv, 218 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2014 Li Na Ma, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Glass-ceramics -- Dissolution
Phosphates
Glass-ceramics -- Structure
Glass-ceramics -- Thermal properties

Thesis Number

T 10615

Electronic OCLC #

902734900

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